|Straw Use - 72
Project Leader and Principal UC Investigators
John B. Dobie,Residue Utilization (RM10)
W.N. Garrett, The Value of Rice Straw as Animal Feed (RM9)
John B. Dobie
H.G. Walker (WRRL-USDA)
G.O. Kohler (WRRL-USDA)
STRAW USE INSTEAD OF DISPOSAL
Although rice straw has had limited or no use in the past, the picture may change because of fiber scarcities and the search for alternatives to burning. Adding supplements and packaging in bite-size pieces alters the comparatively low feed value and poor palatability of rice straw as livestock feed. Developing a market for this by-product, however, will require the ability to deliver straw for processing on a regular and dependable basis. As demonstrated by the rainy October of 1972, that may be hard to do in some years.
The proper package for feeding rice straw to cattle, and the animal productivity expected, have been determined at the Agricultural Experiment Station. Rice straw can be cubed or pelleted with 1-5% added bonding agent or 15% or more of ground barley or almond hulls. Results are best when the straw is supplemented with these or other feed ingredients plus about 3% of a commercial binder. An over-wintering ration containing 70-75% rice straw can be cubed and fed with satisfactory results.
Analysis of several systems of harvesting and processing rice straw for feeding indicates the economic feasibility of either baling or stationary cubing of combine-harvested straw, particularly with a favorable harvest season. Baled straw will require additional processing but has a market potential for several uses. Stationary cubing can produce a finished feed product suitable for over-wintering cattle but must handle 4-5,000 acres of straw to be profitable. (RM 10)
RICE STRAW AS A FEEDSTUFF
Considered as a feedstuff, rice straw is low in digestible nutrients (about 40%) and is deficient in protein, phosphorus, calcium, and some trace minerals. It is high in silica (about 14%), which probably interferes with digestion of the cellulose. Proper treatment, however, can increase its digestibility and palatability. Animals fed a nutritionally balanced ration containing 65% treated straw gained 40% more than animals given the same ration with untreated straw. The treatment with sodium hydroxide or ammonia is still under experiment by the USDA and UC, so it is too early for economic studies of this use. (RM9)